What app did you use to open the PDF originally and send to Adobe Reader? We've discovered that some apps are sending the file as "Read Only" and I'd like to rule out this possibility. Additionally, can you please send the file to pawibbel@adobe.com so I can make sure it's not something specific to the PDF you're editing?

After exchanging emails with vieji21, we were able to reproduce the problem. We are working on a fix and hope to have it in a release soon. Thank you for reporting the issue and I apologize for the bug =).